Re: [dpdk-stable] [dpdk-dev] [PATCH] net/i40e: fix VF Tx bytes

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 7/11/2017 8:56 PM, Stephen Hemminger wrote:
> On Sat,  8 Jul 2017 15:54:25 -0400
> Qi Zhang <qi.z.zhang@intel.com> wrote:
> 
>> CRC size on Tx path is not necessary to be excluded.
>>
>> Fixes: 98abce237ba7 ("net/i40e: fix VF statistics")
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
>> ---
>>  drivers/net/i40e/i40e_ethdev.c | 3 ---
>>  1 file changed, 3 deletions(-)
>>
>> diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
>> index 71cb7d3..0585869 100644
>> --- a/drivers/net/i40e/i40e_ethdev.c
>> +++ b/drivers/net/i40e/i40e_ethdev.c
>> @@ -2353,9 +2353,6 @@ i40e_update_vsi_stats(struct i40e_vsi *vsi)
>>  	i40e_stat_update_48(hw, I40E_GLV_BPTCH(idx), I40E_GLV_BPTCL(idx),
>>  			    vsi->offset_loaded,  &oes->tx_broadcast,
>>  			    &nes->tx_broadcast);
>> -	/* exclude CRC bytes */
>> -	nes->tx_bytes -= (nes->tx_unicast + nes->tx_multicast +
>> -		nes->tx_broadcast) * ETHER_CRC_LEN;
>>  	/* GLV_TDPC not supported */
>>  	i40e_stat_update_32(hw, I40E_GLV_TEPC(idx), vsi->offset_loaded,
>>  			    &oes->tx_errors, &nes->tx_errors);
> 
> Whether or not CRC is included in length statistics has been an ongoing
> problem in DPDK.  The Linux and BSD standard is to exclude CRC from number
> of bytes; Cisco includes it, and Juniper does not.
> 
> For application consistency across real and virtual devices, all
> statistics for both transmit and receive in DPDK must NOT include CRC bytes.

In case missed, Qi sent a new version of patch with more comment [1].

It seems CRC is not counted at first place, that is why it has been
excluded.

So CRC bytes are not counted, even after this patch.

[1]
http://dpdk.org/dev/patchwork/patch/26690/

> 
> Is this still an issue in DPDK drivers? Do I need to put it on the
> TAB agenda? Is it not clear in the documentation?
>